Referring to FIG. 18, there is illustrated a conventional washing and drying machine. Horizontally mounted in housing 1 of the machine is cylindrical water tub 3 which is elastically supported by a plural number of suspensions 2 absorbing vibration of water tub 3 during a washing operation. In water tub 3, cylindrical rotary drum. 5 for holding laundry articles 4 to be washed or dried (referred to as clothes hereinafter) is mounted horizontally and rotatably, which is rotated by rotator 6a of driving motor 6.
Mounted on an inner surface of rotary drum 5 are a plural number of baffles or vanes (not shown) for agitating clothes 4. A plurality of small openings 5a are formed in a cylindrical wall portion of rotary drum 5. Formed in a front wall of housing 1 is door opening 1a for loading and unloading clothes 4 in and from rotary drum 5, which is closed or opened by door 7. Mouth 3a of water tub 3 and mouth 5b of rotary drum 5 face door opening 1a of housing 1, mouth 3a of water tub 3 being connected watertightly to door opening 1a through bellows 8 attached therebetween. Formed on a lower portion of water tub 3 is drain 9 for allowing water therein to be drained, to which one end of drain hose 11 is connected through water outlet valve 10 disposed therebetween, while the other end of drain hose 11 is disposed to outside the machine.
Disposed in front of mouth 5b of rotary drum 5 is air injection opening 14 for allowing drying air heated by heater 13 to flow into rotary drum 5, the heated drying air being forced to flow by blower 12. Disposed beside driving motor 6 is circulation duct 15 for removing moisture from the drying air flowing out of rotary drum 5 and water tub 3, which has one end connected to air outlet 16 formed in the lower portion of water tub 3 and the other end connected to blower 12. Mounted behind water tub 3 is water inlet valve 17 for controlling flow of water supplied through water inlet hose 18.
Washing and drying operations of the aforementioned machine will now be described. Clothes 4 and detergent are placed in rotary drum 5 through door opening 1a, and then the machine is turned on. Water inlet valve 17 opens a passageway to water tub 3 to introduce water into water tub 3 and rotary drum 5. After a predetermined amount of water is supplied to water tub 3 and rotary drum 5, a washing cycle is performed, wherein driving motor 6 starts to rotate rotary drum 5. After a period of time, driving motor 6 is stopped and drain valve 10 is opened, so that used water is drained from rotary drum 5 and water tub 3 through drain hose 11 to the outside of the machine. Next, water tub 3 and rotary drum 5 are refilled with fresh water in a manner as mentioned above to initiate a rinsing cycle. After rinsing clothes, drain valve 10 is opened to drain water from rotary drum 5 and water tub 3. Then, rotary drum 5 is rotated by driving motor 6 to perform dewatering cycle for removing water from the clothes 4.
After the completion of the aforementioned washing operation, a drying operation is initiated. During the drying operation, rotary drum 5 is rotated at a low speed by driving motor 6 to tumble clothes 4, and air, forced to flow in a direction indicated by arrow 19 by blower 12, is heated by heater 13 and then introduced into rotary drum 5 through air injection opening 14. The heated air extracts moisture from the tumbling clothes 4 and then passes through openings 5a, water tub 3 and air outlet 16 to circulation duct 15.
At this time, water inlet valve 17 opens a passageway to circulation duct 15 to introduce water thereto. The water introduced into circulation duct 15 lowers temperature of the heated air containing moisture from clothes 4 to thereby condense the moisture. Then, thus dehumidified air is returned to blower 12. The cooling water and the resulting condensation are drained through drain valve 10 to the outside of the machine. Clothes 4 in rotary drum 5 are dried by forcing the heated air to flow through a circulation path made up of blower 12, heater 13, air injection opening 14, rotary drum 5, water tub 3, air outlet 16 and circulation duct 15.
In this conventional machine, most of heat used in drying clothes 4 is released into surroundings by the drained cooling water and condensation, and radiation of housing 1, without being reused.
Therefore, there has been proposed a drying machine employing a heat pump which is provided with a compressor for compressing coolant, a heat radiator for dissipating heat of the compressed coolant, a throttle valve for lowering pressure of the compressed coolant, a heat absorber for allowing the low-pressure coolant to absorb heat from ambient air and a pipework for allowing the coolant to circulate through the compressor, the heat radiator, the throttle valve and the heat absorber (see, for example, Japanese Patent Laid-open Publication No. 1999-178289).
However, the compressor, the heat radiator, the throttle valve and the heat absorber are connected by the pipework made of, e.g., copper, to circulate the coolant therethrough; and, therefore, if the heat pump experiences severe vibration, connection portions of the heat pump may be structurally weakened by the vibration or fatigue failure of the pipework may take place due to resonance. The washing and drying machine, compared to the drying machine performing only drying operation, provides the dewatering cycle during which rotary drum 5 rotates at a high speed thereby causing severe vibration of the machine. Further, since rotary drum 5 of the washing and drying machine has a horizontal rotational axis, rotational vibration of rotary drum 5 is stronger than that of a rotary drum having a vertical rotational axis. Therefore, it is essential to isolate the heat pump from the vibration of rotary drum.